What Divided by 81 Equals 9?
Methods
Setting up the problem:
In a problem like this, the “what” means that we’re working with a variable. The most common variable used in math is “x”. So, we could say what number, x, when divided by 81, equals 9?
Solving What Divided by 81 Equals 9
Here’s how you would set up this question as an equation:
x
81
=
9
\frac{x}{81} = 9
81 x = 9
The goal of the problem is to solve for x. To do this we need to change the equation so that x is alone on one side of the equation.In this case, we can do that by multiplying both sides of the equation by 81, resulting in this equation:
x
=
9
∗
81
x = 9*81
x = 9 ∗ 81
Then we simplify and find our answer:
x
=
729
x = 729
x = 729
So, the answer to the question “What divided by 81 equals 9?” is 729.To prove this, we can take the original problem:
x
81
=
9
\frac{x}{81} = 9
81 x = 9
And insert 729 in the place of x:
729
81
=
9
\frac{729}{81} = 9
81 729 = 9
Because this is true, the answer must be correct.
Practice Other Division Problems Like This One
If this problem was a little difficult or you want to practice your skills on another one, give it a go on any one of these too!
What divided by 84 equals 47?
44 divided by what equals 38?
What is 8/10 divided by 35?
What is 15/14 divided by 6/7?
What is 30 divided by 1/5?